The present invention relates to hand-held power tools.
One of such hand-held power tools is disclosed for example in the German patent document DE 195 407 18 A1, in which a drive strand in uncontrolled operational situation, such as for example the situation which can occur during a sudden turning of a machine housing after fixing of the tool, is blocked with a machine housing with a jerk. The hand-held machine tool for this purpose is designed with a detecting device which recognizes the uncontrolled operational condition and then form lockingly connects a blocking device of the drive strand with the machine housing. The blocking device for this purpose has a locking member which is displaceably supported in the machine housing radially in direction of the drive member in the drive strand, and is bringable radially into the form-locking engagement with a locking toothing formed on the drive member. The disadvantage of this solution is that the radial arrangement of the locking member to the locking toothing requires a relatively great radial space. The engagement of the locking member is performed relatively close to the rotary axis of the drive strand, so that high blocking forces act on the locking member and require an especially stable design of the blocking device. Moreover, relatively high disengaging forces are required to bring the blocking member after the blocking of the drive strand with the machine housing, again out of the engagement with the locking toothing.
Accordingly, it is an object of present invention to provide a hand-held power tool which avoids the disadvantages of the prior art.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention, resides, briefly stated, in that the locking member and the blocking member are bringable in engagement with one another axially in direction of a rotary axis of the blocking member.
When the hand-held power tool is designed in accordance with the present invention, the inventive arrangement of the locking member and the blocking member provides for a lowering of the structural loads caused by their engagement. In addition it is guaranteed that the blocking device after the release of the blocking device is again bringable to its initial position in a disturbance free manner. Moreover, the axial arrangement of the blocking device provides a flexible and space-saving design of the hand-held power tool.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.